All the irregularities of land and oceans, which vary in age, origin, size and shape, are called relief. Its main forms are ridge, hollow, mountain, saddle and hollow.
Definition
What is hollow? This is an elongated recess in the area. The lines that are located at its lowest points are called thalwegs (watercourses). The sides of the hollow form slopes, ending with brows. Its bottom goes down gradually.
This lowering of the earth's surface occurs mainly due to erosion, has an average depth of three to fifteen meters. The length can reach up to one and a half kilometers.
What is hollow? This lowland is the result of the impact on the soil of melt and storm water flows. At the same time, suffusion is present - the process of removal of the smallest particles of minerals by ground flows. Roughness is typical for steppe and forest-steppe zones. If the blurring of the hollow continues, then after some time it will turn into a beam.
What is hollow? This is a kind of "trough", the bottom of which is flat, swampy, and the slopes are soddy, or covered with shrubs and trees.
Varieties
Among the types of hollows, the following geographical features are distinguished:
- Ravine. It is a narrow hollow, characterized by exposed and steep sides.
- Gorge. It is considered a ravine in the mountains.
- Valley. Serves as a wide elongated recess, the slopes of which are gentle.
- Beam. It is a large uneven surface of the earth, much larger than a ravine, the slopes of which are covered by diverse vegetation.
On the terrain plan, the hollow is shown using concave contour lines depicted in the direction of lowering the relief. Also, its varieties are holes, canyons and so on.
